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Re: Downconverter noise

> > I might have misunderstood the question, but of the 50 or so AIDC
> > 3731's  I've distributed here in the UK, all of them have produced a
> > significant increase in noise level and S meter reading when hooked up
> > it might be S3 or it might be S7.
> I can tell you that form my experience you do hear an increase in noise
> with the d/c on, but it certainly isn't enough to move the s-meter more
> than a unit or less.  It's certainly not 5 units.

My d/c does the same thing.  The S meter is maybe 5 to 7 S units up without
any antenna connected.

But maybe it is because I have a pre amp as part of the d/c.  The 3731 I
have which was reworked by K5GNA has the d/c and pre amp as part of one
unit.  I have placed a small 10 db CATV type barrell pad inline just before
the radio to lower the noise level.

Also if I turn on my antenna mounted preamps for 2m or 440, the noise level
does the same.....

Therefore is it possible that you fellows are talking different things but
the same.  Maybe the d/c makes no difference in the noise but the pre amp
does ??

sunny Sundridge, Ontario, Canada

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